A year and a half ago, after the unexpected success of Valkyrie and his brilliant, career-changing cameo in Tropic Thunder, Tom Cruise managed to pull that career out of morass of batshit that it'd fallen into after the hyper-fueled Rally's commercial couch hump and PR disaster that was his Oprah appearance. Five years later and the career of Tom Cruise -- who realized that he couldn't bend the public perception through the sheer will of his antics -- has been partially resurrected, in some part because the bar has been so lowered. Many of us have realized that we'd rather watch crazy-cakes Cruise in an action movie built around character than we would a big-budget spectacle built exclusively around action sequences. There aren't many screen idols left, and when the alternative is a 3D remake, a comic book movie, or $200 million 120-minute sequel to a toy commercial, an actor like Tom Cruise in a movie like Knight and Day feels strangely refreshing.

The irony, however, is that -- if we were living in a pre-Transformers world -- Knight and Day is as generic as they come -- a generic spy film bred with a generic romantic comedy. But in this marketplace, it feels almost new, buoyed by the novelty of seeing Tom Cruise in a genre with which we haven't seen him (in Cruise's 30-year career, he's never really carried a comedy, much less a romantic one). And though the one-liners don't particularly suit Cruise (some of them are bad enough that they wouldn't even suit Willis or Schwarzenegger in their prime), he's not what's wrong with Knight and Day. Cruise -- whose on-set professionalism borders on sociopathic -- works in this role precisely because of his public perception -- look up "crazy" in the Urban Dictionary, and Tom Cruise is literally the definition. And until around the three-quarters mark of Knight and Day, we're not meant to know for sure whether Cruise's character -- Roy Miller-- is a nutjob rogue federal agent or the only sane person left in the FBI. Cruse's methodical brand of crazy is perfect for the role -- he's calm, cool, and collected, but behind those eyes and underneath that manic grin, there's a wackjob lunatic screaming to get out.

Unfortunately, the rest of the film doesn't live up to performance of Cruise. The casting of Cameron Diaz is not just atrocious, but a borderline 8th Amendment violation -- she represents the worst of the romantic comedy genre and -- because her character is so unrelentingly dumb -- she's also typical of a lot of horror-movie heroines. I don't know how many times during the movie the audience I sat with sighed a collective note of "Jesus, Lady" exasperation at her character's wanton dumbfuckery, but there were more than a couple of moments where a few moviegoers couldn't help themselves from yelling "Don't open the door!" as she opened the door for the eleventy billionth time. You can't buy that kind of stupid -- it has to be bred and imported from New Jersey.

James Mangold -- whose track record (3:10 to Yuma, Walk the Line) doesn't suit this genre particularly well, doesn't hold up his end of the bargain, either. While the action sequences -- and there are plenty of them to keep the first half of Knight and Day moving -- are fun, the rest of the movie withers whenever Cruise and Diaz are asked to establish the romance. There's no chemistry between their characters, and to be honest, Tom Cruise has never had a particularly good chemistry with the women in his films (read into that what you'd like), and that's exacerbated where the romantic chemistry is meant to propel half the film. Moreover, Mangold is obsessed in K & D with the super-extreme close-up shots, and neither the 48-year-old face of Tom Cruise nor the blotchy skin of Cameron Diaz support shots tight enough to reveal their pores (I might note that there are very few actors over the age of 30 that warrant super-tight close ups that are then magnified by 100 on the big screen).

But for the first 45 minutes, and the last half hour (save for the cringy final scene), Knight and Day is as good a summer action film as you could ask. In the opening scenes, Roy Miller uses Cameron Diaz's June to sneak what we later find out is a perpetual energy battery onto a plane where -- as June is holed up in a bathroom plotting a mile-high session with Roy -- he kills everyone on board, including the pilots, before crash-landing the plane in a corn field. Roy drugs June to sleep (a repeating plot device in the film that allows Mangold -- because the film is told from June's perspective -- to back out of a lot of impossible traps without explanation) and the next morning, she wakes up in her Boston apartment, unsure of the previous night's events.

The reality of those events are soon confirmed, however, when federal agents -- led by Peter Sarsgaard's Agent Fitzgerald -- take June into custody, which leads to a PFA (pretty fucking awesome) series of action sequences on Boston's I-93, which almost justified by itself the $15 billion Big Dig project. There's little plot after that -- Roy Miller has to locate the inventor of the perpetual-energy battery (Paul Dano) and protect him from assassins, which basically gives Mangold an excuse to set up action sequences in a half-a-dozen different locations (a tropical island, a train in the Alps, Germany, and Spain), as Roy continues to protect June, while June continues to question Roy's intentions and make really fucking stupid decisions.

Ultimately, I liked Knight and Day, but I wish I could've liked it more. As one of four people in the known world who still likes Tom Cruise -- the actor -- my expectations were perhaps a little high, which perhaps shaded my slight disappointment in the film. I was willing to forgive Mangold's disjunctive and completely inappropriate stylism (I have no idea what he was going for, but whatever it was, it failed), the excessive use of green screens, the bad score, and, at times, the painful dialogue, because of Cruise's beguiling insanity. But it's next to impossible to forgive the weaknesses presented by Diaz -- both in character and in performance. It was Heiglian in its badness, and Knight and Day deserved a more appealing female lead with better comic timing and an ability to sell her action scenes -- a Charlize Theron, or Christina Applegate, or Jamie Lee Curtis in her prime. There are a lot of faults in Knight and Day, but while Cruise obscures them, Diaz exacerbates them.

All of which is to say: I'd give Knight and Day a soft recommend, but if you see it, wear one of those As Seen on TV Eye Patches that allow you to block out certain characters in movies, and set it on Cameron Diaz. The movie will be 72 percent better.